The organizers of the Ultra Music Festival have declared their world-famous Miami concert “adults only” following a 2014 event in which gatecrashers trampled a security guard and a 21-year-old attendee died of a drug overdose.

Ultra leaders announced on the festival’s website Tuesday morning that the electronic dance music bacchanal — which attracts some 160,000 each year to Miami’s Bayfront Park — will ban minors come March 2015. The event has been open to all ages since it began in Miami Beach in 1999.

Ultra’s head of security, former Miami Beach police chief Raymond Martinez, said the new age limit wasn’t related to the trampling of security guard Ericka Mack or the overdose of Adonis Pena Escoto. But in announcing the change, organizers said they were concerned about safety.

“This decision has been made to reinforce and promote the safety of all Ultra Music Festival fans and to ensure the overall enjoyment of all future attendees,” organizers said in a statement.

The security of the high-profile festival and the well-being of concertgoers has been at question since the opening night of this year’s event, when a crowd toppled a chain link fence and trampled Mack, who suffered a broken leg and a fractured skull and spent weeks at Jackson Memorial Hospital. Her attorney did not respond to a request for comment.

Also that weekend, police began investigating the death of Pena Escoto, who was found unresponsive in a car after attending the event. According to the county medical examiner’s office, the young man’s death was accidental, caused by a drug overdose.

Following the chaos, Miami Mayor Tomás Regalado called unsuccessfully for an end to the event. Commissioners ultimately kept the city’s contract with the festival’s operator in April, but required that Ultra hire more cops, erect better fencing and set up mental-health and drug stations operated by health professionals.

At the time, there was also some talk about making Ultra an 18-and-over event. Regalado said on Tuesday that he still believes downtown Miami is the wrong place for Ultra, but praised organizers for agreeing to keep kids out.

“I think that it’s the best decision they could have ever made,” he said. “That was one of the main issues, the concern for minors. And I think it would be a much better festival now.”

The news of the change broke over the weekend as Twitter users began posting new handbills advertising the start of Ultra’s pre-ticket registration next week. The fliers also warned of a zero-tolerance policy against the possession, sale and use of illicit drugs.

Ultra is scheduled next year for March 27, 28 and 29.

Martinez, the head of security, said the festival’s leaders have been thinking about improving safety and the overall festival experience for months. He said organizers took a look at the overall percentage of ticket sales to minors and polled some who went to the event before banning minors.

With minors, “you get into a whole different realm. You’re talking about juveniles and these are large crowds. It’s very similar to a nightclub type of thing,” he said. “The consensus was that it would be a better event if you eliminated all-ages.”